TUCSON, Ariz.- Sophomore starter Sean Rierson tossed his second complete game of the season in Arizona's 5-1 series opening win over UC Riverside at Frank Sancet Field on Friday night. The pitching performance improves Arizona's record to 26-15 overall while UC Riverside falls to 22-18.

The righthander scattered six hits over nine innings to earn his team-high seventh win of the season. He struck out eight and walked just one on 122 total pitches, while preserving a tenuous one-run lead for three innings. The Highlanders placed runners in scoring position four different times only to see the second-year Wildcat escape unscathed each time. The complete game was the fourth of the season for the Arizona pitching staff.

Backing up Rierson was an impressive Wildcat defensive effort. Shortstop Brad Hassey made spectacular play on Randy Blood's second inning ground ball hit deep in the hole between short and third. The senior glove man backhanded the ball and made a strong throw to Pat Reilly at first to narrowly get the hard charging Blood.

Moises Duran and Rierson added another defensive gem in the sixth on Adam Suess' grounder between first and second. Duran fielded the sharply hit ball that eluded Rielly's glove and fired a bullet to a moving Rierson at first to get the out.

Offensively, the Wildcats rallied from a sluggish start that saw UCR starter AJ Shappi retire the first 10 hitters he faced. Trailing 1-0, a defensive miscue by Highlander shortstop Scott Powis on Justyn St. Clair's ground ball ended the perfect game and eventually led to the tying run. Senior Chris Cunningham plated his classmate with Arizona's first hit in the game, a double to straight away center, to even the score at 1-1.

The Wildcats took the lead an inning later on designated hitter Ken Riley's single to left field that scored John Hardy from third.

The Wildcats tacked on three more insurance runs in the bottom of the eighth on Cunningham's second run-scoring hit of the game and pinch hitter Richard Mercado's two-out, two-RBI single through the left side of the infield with the bases loaded.

A tiring Rierson (7-2) then closed out his second career complete game with runners on first and second by inducing Rich Hofman to fly out to Brian Anderson in center to end the game. Shappi (4-3) was tagged with loss, giving up all five of Arizona runs in 7.2 innings. He struck out seven and walked two.

Cunningham was the lone Wildcat to collect multiple hits in the game finishing with two of Arizona's six hits. Hassey extended his hitting streak to a team-season-high 13 straight with an infield single to short in the sixth inning.

The Wildcats and Highlanders return to action for game two of the series on Saturday at 7 p.m. Marc Kaiser will toe the rubber for the Wildcats.